Tuesday, September 27, 2011

There are, I think, some gaps in the Bartels and Pizarro argument -- especially since there might be a pretty loose connection between real consequentialist moral thinking and tending to say "push the fat man!" when given a trolley problem. Quite possibly, undergraduates tending toward psychopathic personality will say the latter even if they aren't very good representatives of genuine consequentialist moral thought.

Josh Rust and I, in our study of the moral behavior of ethics professors, found that ethicists favoring deontology vs. consequentialism vs. virtue ethics all behaved about the same, both by self-report measures and by direct observational measures. To the extent there was a tendency, it was for virtue ethicists to self-report slightly worse behavior.

Update, Sept 28: In the comments I think I more clearly articulated my concern about Bartels and Pizarro than I did above, so I paste it here: "As a cartoon, imagine that you have a group of respondents who don't really think ethically about the dilemmas at all and just think it's funny to tell the prof to push the fat man, and suppose that psychopathic personality types are overrepresented in that group. Then you get the Bartels and Pizarro results, but there's no relationship with consequentialist thinking."

Monday, September 19, 2011

Bizarre views are a hazard endemic to metaphysics. The metaphysician starts, seemingly, with some highly plausible initial commitments or commonsense intuitions -- that there is a prime number between 2 and 5, that I could have had eggs for breakfast, that squeezing the clay statue would destroy the statue but not the lump of clay -- thinks long and hard about what they imply, and then ends up positing a realm of abstract Platonic entities, or the real existence of an infinite number of possible worlds, or a huge population of spatiotemporally coincident things on her mantelpiece. I believe there is not a single detailed exploration of fundamental issues of metaphysics that does not, by the end, entangle its author in seeming absurdities (sometimes advertised as "surprising conclusions"). Rejection of these absurdities then becomes the commonsense starting point of a new round of metaphysics, by other philosophers, which in turn generates a complementary bestiary of metaphysical strangeness. Thus are philosophers happily employed.

I see three possible explanations of why philosophical metaphysics is never thoroughly commonsensical.

One is that a thoroughly commonsensical metaphysics wouldn't sell. It would be too boring. A famous philosopher can't say only obvious things. The problem with this explanation is that there should be at least a small market for a thoroughly commonsensical philosophy. Common sense might not be quite as fun as Nietzsche's eternal recurrence or Leibniz's windowless monads or Hegel's world spirit, but a commonsensical metaphysics ought to serve at least as a foil; it oughtn't be so downmarket as to be entirely invisible. In the 18th century, Thomas Reid helped found the Scottish school of "common sense" philosophy, and today he is the best known representative of that school -- so one might naturally wonder if Reid's metaphysics is thoroughly commonsensical. It's not. See, for example, his thoughts on the immaterial souls of vegetables. Nor is G.E. Moore's, when he develops his positive views in detail, despite his famous "Defence of Common Sense". See, for example, his treatment of sense data.

Another possible explanation is that metaphysics is incredibly hard. There is a thoroughly commonsensical metaphysics out there to be had; we simply haven't pieced it together yet. Maybe someday someone will finally bring it all together, top to bottom, with no serious violence to common sense at any point in the system. I fear this is wishful thinking against the evidence. (In a future post I hope to argue the point in more detail for the metaphysics of mind.)

A third explanation of the bizarreness of metaphysics is this: Common sense is incoherent in matters of metaphysics. Detailed examination of the consequences of our commonsense opinions inevitably leads to contradictions. To develop a coherent metaphysics in detail thus necessarily involves rejecting some aspects of common sense. Although ordinary common sense serves us fairly well in negotiating our everyday social and physical environments, it has not proven a reliable guide in cosmology or microphysics or neuroscience or evolutionary biology or probability theory or structural engineering or medicine or macroeconomics or topology. If metaphysics more closely resembles items in the second class than in the first, as it seems to, we might justifiably be suspicious of the dependability of common sense as a guide to metaphysics. Undependability does not imply incoherence, but it does seem a natural next step in this particular case, especially since it would generate a tidy explanation of the historical fact that detailed metaphysical systems are never thoroughly commonsensical.

Thus, I am endorsing the incoherence of common sense in matters metaphysical as an empirical hypothesis, justified as the best explanation of an empirically observed pattern in the history of philosophy.

Wednesday, September 14, 2011

I’m engaged in a certain exercise. You might doubt the value of this exercise, but it’s a traditional philosophical exercise, and I’m a philosopher. The exercise is attempting to prove the existence of an external world beyond my own stream of experience.

As I mentioned in a previous post, the two most historically famous proofs of the external world appear to be unsatisfactory: Descartes’s because it turns on the dubious claim that the idea of perfection could only be caused by a perfect being, and G.E. Moore’s because it starts from the question-begging premise “here is a hand”.

My strategy is this: First, I assume introspective knowledge of my current sensory and other experiences, memory of past experiences back to the beginning of the exercise, and the general concepts and methods of science insofar as those are stripped of any presupposition of a world beyond my stream of experience. Then, I attempt to find experimental evidence sufficient to justify belief in a world beyond my stream of experience, as the best scientific explanation of patterns in my stream of experience.

In Experiment 1, I did something that seemed like programming a spreadsheet to determine whether various four-digit numbers were prime, and I also guessed whether those numbers were prime. As confirmed by subsequent hand calculation, the seeming spreadsheet did a far better job than I did at correctly marking the primes, and the best explanation appeared to be that something exists with calculating abilities exceeding my own – at least insofar as the “I” is conceived solipsistically, as constituted entirely by my stream of experience.

Experiments 2a and 2b:

Now I will try a second experiment, using an apparent confederate. I will call this apparent confederate “Alan”, though without meaning to presuppose that he exists as anything but a figment of my own stream of experience.

This “Alan”, by what I think of as prearranged instructions, gives me a list of 20 three-letter combinations to memorize (“EMA”, “GLL”, etc.). The list of three-letter strings appears orally, by which I mean that I seem to hear him say the 20 three-letter combinations. He appears to present the list twice. I then attempt to freely recall the letter-combinations from the list, offering up six guesses – the three-letter strings that it seems I can recall without prompting. “Alan” then presents me visually with a forced-choice recognition test: 40 three-letter combinations, half of which he says are new and half of which he says are the original 20, in random order. I select 20 of the 40 as my best guess as to which are the old ones. I feel high confidence about 10 of these guesses. We then repeat the same experiment with a second set of three-letter combinations. This time I offer up eight guesses in free recall and in the 40-item recognition test I again feel high confidence about 10 items.

Now, if nothing exists beyond my own stream of experience, then the forgotten items on these lists should not, it seems, be stable. They exited my mind – either as measured by free recall or by the stricter measure of recognition – and thus they exited the universe. Thus, when Alan seems to present me with these lists a second time, which he will shortly do, nothing endures across time that could anchor the forgotten items in place, ensuring that the new perfectly matches the old. The seemingly re-presented items could be any set of plausible items; my mind has unconstrained liberty to invent any letter combinations that seem reasonable candidates to span the gaps in my memory. On solipsism, the present needn’t preserve the details of the past; it need only preserve, seemingly can only preserve, the details of the past that I remember.

However, Alan now shows me evidence that undercuts this solipsist picture – evidence suggesting that the 20 three-letter combinations that were the “right” answers in each test were in fact anchored in place and stable across time rather than created at liberty anew. He shows me, first, the lyrics of “Take Me Out to the Ball Game”, and he tells me that the first 20 three-letter combinations were the letters, in reverse order, from the end of the chorus of that song (excluding spaces, punctuation, and two repeated letter combinations). As I look through that list of letter combinations (“EMA”, “GLL”, “ABD”, etc.), it is quite evident to me that this is the case: I am forcefully struck by the fact that the letter combinations that I do seem to recall from the original list fit exactly into that pattern, though I was entirely unaware of that pattern at the time they were originally presented. Comparing my free recall and recognition lists with the reversed-ballgame song, I see that 5 of my 6 freely recalled letter combinations appear in that song (one guess, Alan tells me, was wrong) and that 15 of the 20 I seemed to recognize were correct, including all 10 about which I felt confident in the recognition test. The other stimulus, Alan tells me, was similarly derived in backwards chunks from a sentence from George Berkeley: “In short, if there were external bodies, it is impossible we should ever come to know it; and if there were not, we might have the very same reasons to think there were that we have now.” Here, Alan tells me I accurately freely recalled 7 of the 20 combinations (having made one erroneous guess out of eight) and correctly recognized 16 out of 20, including all 10 about which I had felt confident.

Why should I believe that these lists now shown to me by this seeming Alan actually match the original ones presented? Their structure suggests so: Although I am not assuming the existence of ballgames or peanuts or cracker jack, it is one of the background assumptions of this exercise that I permit myself my existing conceptualizations, stripped of any commitment to a really existing external world. And my conceptual structure contains the song “Take Me Out to the Ball Game”, in which these words appear as indicated. Likewise, it’s part of my conceptualization of George Berkeley that this is just the sort of thing he would say and of Alan’s sense of humor that he would use this sentence to generate the stimulus. While it’s remotely possible that from the fragments that I happened to remember such natural-seeming structures could be found post-hoc to fit, that would seem to require enormous happenstance. Suppose that there were as many as a trillion possible strings of text Alan could have used, per the instructions I seem to remember having given him, to generate suitable test material, given present purposes. And suppose conservatively that English allows only about 1000 viable, roughly equiprobable, plausible three-letter combinations (it would be about 18,000 if all 26 letters could appear in any combination). Still there would be only about a one in ten billion chance that I could find two matches from that trillion strings for my two sets of ten confidently recognized three-letter combinations.

A better explanation, I venture, than such a boggling chance is that these remembered letter combinations were indeed generated in something like the manner described by this “Alan”, and thus that the lists Alan is now showing me do, as he says, match the original, in both their remembered and their unremembered parts. In other words, this pattern among my remembrances was not constructed anew but was present from the beginning in the original experience of hearing the letter combinations, including in the unremembered parts of that experience, since without those unremembered parts the strings would not fit the stated pattern. But then these lists, or at least the pattern they reflect, must have endured beyond my conscious ken from the time of original experience to the time at which the pattern was revealed to me, sustained by some mechanism running outside my stream of conscious experience.

Maybe my knowledge of the ballgame song or the Berkeley sentence operated nonconsciously in me to generate those letter combinations from the start? But that hypothesis still involves rejecting the most radical form of solipsism, the form of solipsism currently under discussion, which posits that all that exists in the universe is my own stream of experience. I don’t conclude that I know what, exactly, is beyond my experience – that Alan exists or that the physical list exists – only that something is beyond. That something might be my nonconscious mind.

Maybe my conceptualization of song lyrics and great philosophers is, unbeknownst to me, highly labile, so that although it seems that the lyrics are annoyingly familiar and the quote from Berkeley oh-so-apt, in fact this sense of familiarity and aptness arose wholly for the occasion, via some strange law of relating past and present experience, and the combinations are actually new, perhaps even the words themselves new English words? Then there need have been nothing outside my own conscious experience that endured from the first moment of presentation until now. This objection seems ad hoc given the background rules of this exercise, but in any case, it can be avoided with a third experiment.

Experiment 3:

Experiment 3 is structured much like experiments 2a and 2b, except that the items to be remembered are 20 three-digit numbers. So: I (and “Alan”) run the experiment. Alan tells me, now, that I have correctly freely recalled eight three-number combinations (nine guesses with one error) and have correctly recognized 15 items, including all of the eight combinations about which I felt confident during the recognition test. What suggests the stability of the list in this case? Alan tells me that the 20 three-digit numbers are actually the first 60 decimal places of the long cyclic number that comes from dividing 1 by 1939, the year in which G.E. Moore delivered his famous “Proof of an External World”. This time, instead of trusting in the stability of my conceptualization of song lyrics, I plan to trust to the stability of mathematics, confirming the list’s stability, the existence of the pattern Alan alleges to unite the initial and present stimuli, by long division by hand to 60 decimal places.

But, alas! After the first six digits something has gone wrong. Hand division does not confirm the list; the numbers diverge. Have I made a calculation mistake? No, evidently not, unless I am very deeply confused. Is there, perhaps, no external world or stability to mathematics after all? I suppose I am a biased experimentalist; I am reluctant to draw that conclusion. The number is a bit larger in the 7th digit, so on a hunch, I check the decimal expansion of 1/1938. Indeed, there is a perfect match all the way out to the 60th digit, between the list Alan tells me was the original stimulus and the hand-proven results of my calculation. (N.B.: In subsequent conversation “Alan” confirmed the diagnosis, but that small slice of experience is outside the scope of the experiment and thus out of bounds for now.)

I seem to recall having suggested to Alan that he use a long cyclic decimal expansion or some other readily calculated but unpredictable number string to generate the list for this experiment. Supposing that there were a million suitable pseudo-random number strings from which Alan might have chosen, the odds are over a million to one that all eight stably remembered three-digit combinations would appear among the 20 sets of three digits from one of those million candidate number strings. Again, the more likely explanation appears to be that the eight remembered combinations were indeed generated by the discovered pattern, along with the other unremembered combinations, and thus that the present list matches the original list and consequently that something endured over time, preserving that structure outside my conscious ken, contra the radically solipsistic hypothesis. This conclusion appears justified even though it took some searching to find the driving pattern.

Discussion:

The resolute skeptic will, of course, find joints at which to challenge this argument: Maybe the laws of math aren’t stable over time. Maybe there’s unmediated action at a temporal distance between my first oral experience of the list and my subsequent visual experience of the list. Maybe my memory is so poor that I can’t even trust that I did in fact recall several items correctly and this whole business has been an illusion of the past five seconds. In general, anywhere there is an undefended premise, the skeptic can insert a knife; and all arguments must have undefended premises on pain of regress. But recall the aim of this exercise: It is to provide experimental evidence, in the form not of incontestable proof but rather of inference to the best explanation, for the existence of something beyond my stream of experience, while taking for granted knowledge of my stream of experience and my pre-existing scientific standards and conceptualizations except insofar as those standards and conceptualizations presuppose the existence of anything beyond my stream of experience. That, I tentatively believe I have done.

If philosophical moral reflection tends to promote moral behavior, one might think that professional ethicists would behave morally better than do socially comparable non-ethicists. We examined three types of courteous and discourteous behavior at American Philosophical Association conferences: talking audibly while the speaker is talking (vs. remaining silent), allowing the door to slam shut while entering or exiting mid-session (vs. attempting to close the door quietly), and leaving behind clutter at the end of a session (vs. leaving one’s seat tidy). By these three measures, audiences in ethics sessions did not appear, generally speaking, to behave any more courteously than did audiences in non-ethics sessions. However, audiences in environmental ethics sessions did appear to leave behind less trash.

Friday, September 02, 2011

Eighteenth century Scottish "common sense" philosopher Thomas Reid never tires of flogging his opponents with their violations of common sense. Thus, it may seem surprising that he would write this:

[B]oth vegetables and Animals are United to something immaterial, by such a Union as we conceive between Soul and Body, which Union continues while the Animal or Vegetable is alive, & is dissolved when it dies (in Wood, ed., 1995, p. 218-219).

In other words, vegetables have immaterial souls -- or, if not souls exactly, immaterial parts analogous to souls. (Not to worry, there's no Vegetable Heaven [see p. 223].) Although Reid doesn't highlight this point or dwell upon it, it flows very naturally from his general system on which nothing material can be the source of its own movement (including growth).

Because of Reid's reputation as the great philosopher of common sense, I'm examining his work as a test case of the following empirical hypothesis, which I currently consider to be well supported: No philosopher has ever been able to construct a detailed and coherent metaphysics of mind that entirely respects our commonsense intuitions. Not even Reid could do so. (Shall we try G.E. Moore next?)

The conclusion I'm inclined to draw, partly on its own merits and partly as the best explanation of this fact about the history of philosophy, is that our commonsense metaphysical intuitions are, at root, incoherent. Thus, there is no way to build a detailed and coherent metaphysics of mind that entirely respects common sense, making it unsurprising that none of the brilliant minds in the history of philosophy have ever done so.

Update, October 3:
Several people have reminded me in the comments that in Reid's era it might not have been contrary to common sense to suppose that vegetables have some sort of vital essence not wholly material. Reid's remarks about the immaterial souls of vegetables need to be seen in light of that. Still: It's a leap from some sort of vaguely folk-approved vital essence to an immaterial soul (or vegetative soul), and Reid does use the word "soul"; and he contemplates the question of afterlife for vegetables; and his view on these issues is tangled up with his view that physical objects and events have no causal powers of their own but require the constant intervention of immaterial beings -- a view that he explicitly confesses to be at odds with what most ordinary people would accept.

So: I still hold my view that Reid is not wholly able to preserve common sense on this matter, but the issue is more complex than I made it seem above.

A few days ago I posted a discussion of Nick Bostrom's Simulation Argument, which aims to show that there is a substantial chance -- perhaps about one in three -- that we are living in a computer simulation. I raised three concerns about the argument but ultimately concluded that although simulationism is crazy (in my technical sense of "crazy"), it's a cosmological possibility I don't feel I can dismiss.

Bostrom and I had an email exchange about that post, and he has agreed to let me share it on the blog.

So, first, you'll want to read my discussion, if you haven't already, and maybe also Bostrom's article (though I hope the summary in my discussion does justice enough to the main idea for the casual reader).

Bostrom's Reply:

Dear Eric,

Thanks for your thoughtful comments and for posting on your blog.

A few brief remarks. Regarding (A) and deriving an objection from externalism: There are a few things said in the original paper about this (admittedly quickly). For example, what do you think of the point that if we consider a case where we knew that 100% of everybody with our observations are in sims, we could logically deduce that we are in sims; and therefore if we consider a series of cases in which the fraction gradually approaches one, 90%, 98%, 99%, 99.9%, … , it is plausible that our credence should similarly gradually approach one? (There is also the whole area of observation selection theory, which uses stronger principles from which the “bland indifference principle” needed for the simulation argument drops out as an almost trivial special case.)

Regarding (B), I think it’s a somewhat open question how many conscious fellow traveler the average simulated conscious being has. Note that there need be only a few ancestor simulations (big ones with billions of people) to make up for billions of “me-simulations” (simulations with only one conscious person). Another issue is whether it would be feasible to create realistic replicas of human beings without simulating them in enough detail that they are conscious - if not, we have observational evidence against the me-sim hypothesis.

[Regarding the response to A] I don’t accept the slippery slope. As long as there is one non-sim, that person’s grounds for believing she is a non-sim might be substantially different than the grounds of all simulated persons no matter how many sims there are, especially if we accept an externalist epistemology. Compare the Napoleon case. No matter how many crazy people think they are Napoleon, Napoleon’s own grounds for thinking he is Napoleon are different, and (arguably) the existence of those crazy people shouldn’t undercut his self-confidence. It would be very controversial, for example, to accept an indifference principle suggesting that if 10,000 crazy people have thought they are Napoleon, and if (hypothetically) Napoleon does or should know this about the world, then Napoleon himself should only believe he is Napoleon with a credence of 1/10,000. Of course, there are important disanalogies between the sims case and the Napoleon case. My point is only that your argument has a larger gap here than you seem to be granting.

[Regarding the response to B] Agreed. It’s an open question. I wouldn’t underplay the likelihood that many future sims might exist in short-term entertainments or single-mind AIs. I like your suggestion, though, that it might be impractical or impossible to have a solo sim with realistic non-conscious replicas as the solo’s apparent interactive partners – but that point will interact at least with the issue of sim duration. I’ve been solo in my office for half an hour. If I’m a short-duration sim, then probably non-conscious quantities AI will have been sufficient to sustain my illusion of a half-hour’s worth of internet interactions with people. How the openness of the duration/solo question plays out argumentatively might depend on one’s argumentative purposes. For purposes of establishing the sims possibility the non-trivial likelihood of the existence of massive ancestor simulations is sufficient. But for purposes of evaluating the practical consequences of accepting the sims possibility, it might be important to bear in mind that many sims may not exist in long-duration, high-population sims. It seems to me that unless you can establish that most sims do live in long-duration, high-population sims, the sims possibility has more skeptical consequences, and perhaps more of a normative impact on practical reflection, than you suggest.

[Regarding the possible interaction between (B) and (C)] I agree with your reasoning in faq 4. Just to be clear, what I was suggesting in my comment on the interaction between (B) and (C) was not intended as an objection of the sort posed in faq 4. In fact, the second of the two connections I remark on seems to increase the probability that I am a sim (and secondarily, to a lesser extent, that we are sims) by reducing the probability of DOOM/PLATEAU.

...

Bostrom's Response to My Follow-Up:

...

[On Issue A] That was intended as a continuity argument rather than a slippery slope argument. I’m not saying one point should be regarded as equivalent to another point because there is a smooth slope between them, but rather that credence should vary continuously as the underlying situation varies continuously. Is the alternative that I should assign credence 1 to being in a sim conditional on everybody being in a sim, but credence 0 to being in a sim conditional on there being at least one person like me who is not in a sim? Would an analogous principle also hold if we imagine that a single individual could be taken in and out of a simulation on alternating days without noticing the transfer? Folks willing to bet according to those obstinate odds would then soon deplete their kids’ college funds.

[On Issue B] I broadly agree with that. Pending further information, it seems the simulation hypothesis should lead us to assign somewhat greater probability than we otherwise would to a range of outlier possibilities (including variations of solipsism, creationism, impending extinction, among others). To go beyond that, I think one needs to start to think specifically about what motives advanced civilizations might have for creating simulations (and one should then be diffident but not necessarily completely despairing about our ability to figure out the motives of such presumably posthuman people). The practical import of the simulation hypothesis is thus perhaps initially relatively slight but it might well grow as our analysis advances enabling us to see things more clearly.